No, you should not rely on Twilio Programmable SMS if you require delivery of SMS communications to emergency services such as 911 or E911 (US/Canada) or 112 (Europe). Twilio Programmable SMS is not designed for use cases that require delivery to such services. Promising such connectivity to end users would be in violation of Twilio’s Terms of Service.
If you provide a service to end users who may try to send SMS to 911 (or equivalent emergency service) to connect to emergency services personnel through your service, please instruct such users to contact 911 via an alternative method, such as their standard wireless service. Mobile phones in some countries, including the United States, can place emergency voice calls to 911 or 112 even if no SIM card is installed in the device.
More about Text-to-911 in the U.S.:
End users in the U.S. who need to reach emergency services should make a voice call from a mobile phone or landline, if possible. SMS from mobile phones may reach 911, however the United States FCC explains that Text-to-911 has limited support at this time, and voice calls are preferable when possible:
Voice calls to 911 are usually the most efficient way to reach emergency help. For example, voice calls allow the 911 operator to more quickly ask questions and obtain information from the caller, while two-way communication by text can take more time and is subject to limits on the length of text messages. In addition, when you make a voice call to 911, the call taker will typically receive your phone number and the approximate location of your phone automatically.
Can I use Twilio for other types of notifications and alerts?
Absolutely – it is acceptable and encouraged to use Twilio to send notifications that do not directly concern life safety. For example, Twilio may be used to send early warning alerts, public safety advisories, event cancellations, and so on. For critical applications, we recommend building in redundancy and using Twilio notifications in conjunction with other public warning systems, such as sirens, radio, and TV broadcasts.